You need to install those drivers if they don't work out of the box:
Plug the Linksys Wireless-G PCI card into the computer and turn the computer on. Log in as normal.
Navigate to "System," Administration," Networking" and choose the wireless connection you wish to use. If no connection is available and your card is plugged in, continue to Step 3.
Click on "Properties" and make sure "Enable this connection" is turned on.
Set "Configuration" to "Static IP address" only if your Internet Service Provider has given you a static Internet Protocol (IP) address. Enter the IP address in the required field and click "OK."
Check to see if your card is supported. If your Linksys Wireless-G PCI card is not supported by the native Linux driver, check to see if your card is supported by "ndiswrapper".
Navigate to the "Applications" menu and select "Accessories" and "Terminal" to install ndiswrapper. Enter the command
sudo apt-get install ndisgtk
Blacklist the native network driver by navigating to "Applications," "Accessories" and "Terminal." This will open a command-line interface.
Enter the command "
echo -e "blacklist bcm43xx\nblacklist b43\nblacklist b43legacy\nblacklist ssb" | sudo tee -a /etc/modprobe.d/blacklist."
Install the Windows drivers by navigating to "System," "Administration," "Windows wireless drivers" and following the prompts.
Load the new driver module by entering these commands into the Terminal in sequence:
"sudo depmod -a"
"sudo modprobe ndiswrapper"
Repeat Steps 2 and 3. If your Linksys Wireless-G PCI wireless adapter does not work
Read more: How to Set Up a Linksys Wireless-G PCI Card in Ubuntu | eHow.com http://www.ehow.com/how_6821664_set-wireless_g-pci-card-ubuntu.html#ixzz28fKHFr61